4.7 Article

Accurate first-order perturbation theory for fluids: uf-theory

期刊

JOURNAL OF CHEMICAL PHYSICS
卷 154, 期 4, 页码 -

出版社

AMER INST PHYSICS
DOI: 10.1063/5.0031545

关键词

-

资金

  1. German Research Foundation (DFG) within the Cluster of Excellence in Simulation Technology at the University of Stuttgart [EXC 2075]

向作者/读者索取更多资源

The new first-order perturbation theory provides a near-quantitative description of thermodynamics for simple fluids, with constraints on the actual free energy between lower and upper bounds calculated based on first-order perturbation theory. The theory allows accurate interpolation between low and high densities, with a transferable interpolating function for different intermolecular potential types.
We propose a new first-order perturbation theory that provides a near-quantitative description of the thermodynamics of simple fluids. The theory is based on the ansatz that the Helmholtz free energy is bounded below by a first-order Mayer-f expansion. Together with the rigorous upper bound provided by a first-order u-expansion, this brackets the actual free energy between an upper and (effective) lower bound that can both be calculated based on first-order perturbation theory. This is of great practical use. Here, the two bounds are combined into an interpolation scheme for the free energy. The scheme exploits the fact that a first-order Mayer-f perturbation theory is exact in the low-density limit, whereas the accuracy of a first-order u-expansion grows when density increases. This allows an interpolation between the lower f-bound at low densities and the upper u bound at higher liquid-like densities. The resulting theory is particularly well behaved. Using a density-dependent interpolating function of only two adjustable parameters, we obtain a very accurate representation of the full fluid-phase behavior of a Lennard-Jones fluid. The interpolating function is transferable to other intermolecular potential types, which is here shown for the Mie m-6 family of fluids. The extension to mixtures is simple and accurate without requiring any dependence of the interpolating function on the composition of the mixture.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据